<xs:element name="BankAccountNo"> <xs:simpleType> <xs:restriction base="nonZeroString"> <xs:pattern value="[a-zA-Z0-9]([/-]?(((\d*[1-9]\d*)*[a-zA-Z/-])|(\d*[1-9]\d*[a-zA-Z]*))+)*[0-9]*" /> <xs:minLength value="1" /> <xs:maxLength value="20" /> </xs:restriction> </xs:simpleType> </xs:element>